To me sprawl is not a place but a sytle of land use with larger lots, larger ROWs, cul-de-sacs, and winding streets.
Defining sprawl (or the attempt to) is also a good way to spark some debate.
Personally I see sprawl not so much in terms of land use, but in terms of energy and resource. Do you need to drive to function in it? How much fuel do you use to transport yourself and to heat your home? How much energy goes into building it? How much does it cost to maintain it? What resources are necessary just to stay healthy? What external support systems are needed to keep it functioning?
Take 3 different areas of the GTA, North York, Mississauga, and Scarborough. How would you classify these in terms of sprawl? There will probably be a rather wide range of opinions as too how and why people classify them.
Myself, I would probably say that while Mississauga has a built form that is identifiable with sprawl, it also has its own government and tends to look more inward to itself than too Toronto. As Mississauga grows it will make attempts to grow around its own center and develop its own econmic independence rather than just relying on being solely a dormitory of Toronto. Scarborough lies at the other end. It has some small nodes of activity and some economy, but it is still dependant on the central city for its existence. Basically it has a shopping mall. Lying somewhere in the middle is North York which may have some areas that are denser or more urban in nature than most suburbs, has some economic activity, but is still a secondary node to the central city and still functions under the governance of the central city.
Again, thats just my own point of view on the issue and everyone is going to see it differently.
Another defintion might also be "an area of one or two very limited uses and minimal systems of self support and sustainability."